I have a g4 quicksilver and I bought a 1TB sata harddrive to put in it. I also bought a pci card to connect the sata harddrive. I disconnected my other harddrive and put in the OS X disc to load the operating system, but when I get to the screen to choose which disc to install it on, my harddrive doesn't appear. What could be causing this?

Most likely because the disk is new and had not been formatted for Macintosh use yet. Virtually all new drives come formatted for PC use.

When the OS installer disk has fully loaded, go up into the menus and choose Disk Utility to format your new drive first. Make sure it gets formatted and that an APM partition map is used which is required for booting a disk on your PowerPC based Mac.

When that is complete, I'm sure it will show in your installable disks window.

It will not let me go past the "Select Destination" screen. There is no harddrive showing up to install to. Any ideas?

I understand that- that is why I posted about formatting it first when you first get the OSX Installer disk booted- before you even go to the "Destination" screen.

When you boot from the installer disk the first thing you will see is the window that asks you what language to use. Select one and click OK. The very next screen will say "Welcome to the OSX Installer" or similar.

At that point (before you click continue) go up into the "Utilties" menu at the top of the screen. Select "Disk Utility", format the disk correctly and quit "Disk Utility". THEN press continue to go to the Destination screen and your disk will appear.